1. Field Of The Invention
The present invention relates to credit card imprinters and particularly to such imprinters using dual roller platens.
2. Description Of The Related Art
Credit card imprinters in widespread use are generally those in which separate cards or plates, having embossed characters, are used to imprint a joined pile of forms, i.e., a "form set". For example, a form set for recording information relating to a sales transaction may be imprinted with vendor information, from a metal merchant plate, and customer information, from a plastic credit card carried by the customer.
These printers generally have comprised a flat, rectangular printing base on which the credit card, the merchant plate, and possibly auxiliary printers for charge and date are mounted. A platen carriage, containing one roller platen on an axle or two roller platens on separate axles, is pulled over the printing base and impresses a form set with embossed characters from the merchant plate and credit card and from the date and charge printers.
U.S. Pat. No. 4,457,228, assigned to Bartizan Corporation, incorporated by reference herein, relates to a credit card imprinter in which a platen carriage has dual roller platens set on separate parallel roller platen axles. The axle heights are individually adjustable to desired printing levels allowing for adjustment to the different printing elements and thus permitting the use of printing surfaces requiring less accuracy.
In that printing apparatus a platen carriage contains a credit roller platen and a merchant plate roller platen, each mounted on a separate roller axle. Each roller platen axle is perpendicular to and presses upwardly on two horizontal arm members, each having one lower horizontal ledge and one higher horizontal ledge. When a roller platen axle abuts against the lower ledge the platen is held downwardly in position to imprint characters and when the platen axle abuts against the higher ledge, the platen is held idle so that it cannot imprint characters. A lever mechanism switches an axle from the lower ledge to the higher ledge when a shift lever, pivotly mounted on the platen carriage, hits against either of two stops located at each end of the platen carriages, travel across the imprinting base. That dual platen roller imprinting mechanism is comparatively easy to disassemble for service and part replacement and allows each separate height adjustments for both credit card and merchant plate platens.
However, the internal mechanism of the carriage is relatively complex and requires seven separate parts (usually six metal, and one plastic) to perform the function of shifting the heights of the axles.